USB usage - getting started

Posted on May 17, 2011 at 13:43

1) The two USB pins on the STM32 can be used either as USB, USART1, CAN, TIM1 or GPIO. If you want to use it as USB, you have to connect them to the D+ and D- pins on the USB connector.

2) The two other pins on the USB connector is +5V and Ground - you could check this schematic which also shows the USB connection:

http://www.tkjweb.dk/STM32F103ZET6_Board_Rev2.png

3) The USB function on the STM32 is a USB 2.0 full-speed device - so it should be able to handle 480Mbps

4) You should check USB Device library:

http://www.st.com/stonline/products/support/micro/files/um0424.zip

    And the documentation about it:

http://www.st.com/stonline/products/literature/um/13465.pdf

Best Regards

Thomas Jespersen

Posted on May 17, 2011 at 13:43

I thought that only high-speed devices can handle 480Mbps...

Posted on May 17, 2011 at 13:43

Oh, I really didn't know that...

As the USB FS Manual says it is USB Full Speed capable, but not how fast that is?

Best Regards

Thomas Jespersen

Posted on May 17, 2011 at 13:43

The name clearly expresses the speed:

Low Speed = 1.5 Mbit/s

Full Speed = 12 Mbit/s

High Speed = 480 Mbit/s

Whatever Xtra Speed = 5 Gbit/s

STM32F102, 103 is only Full Speed device (must connect to Host or OTG), the F105, 107 is a Full Speed device and FS/LS host (or OTG)

Hw to start? Download the USB developer kit from

http://www.st.com/mcu

, Support files for STM32, and try to get into the source codes of some of the examples.